Apparatus for continuous casting of metal strip

ABSTRACT

Apparatus for the continuous casting of metal strips effected in a water-cooled flow-through mold wherein the metal strip is cast in the shape of a segment of a circle and, subsequent to mold discharge, is carried by a guide track in the shape of a circle segment with provision being made for optimum cooling of the metal strip during passage therethrough by water spray impingement, with a maximal area of the guide track and strip passing therethrough being exposed to unimpeded spray cool treatment, and with minimal strip guide structures cooperating with the guide for maximum open area exposure of the cast billet for cooling.

United States Patent 1191' Carle 1411 July 24,1973

[ APPARATUS FOR CONTINUOUS CASTING OF METAL STRIP [211 App]. No.2 189,992

[52] [1.8. CI. 164/282, 164/283 [51] Int. Cl 322d 11/12 [58] Field of Search 164/82, 282, 283

[56] References Cited UNITED STATES PATENTS 3,358,744 12/1967 Rossi 164/282 3,39l,725 7/1968 Rossi...

702,719 l/l954 Great Britain 164/283 Primary Examiner-R. Spencer Annear AttorneyDavid H. Sernmes 57 ABSTRACT Apparatus for the continuous casting of metal strips ef' fected in a water-cooled flow-through mold wherein tfiemera'l strip is cast in the shape of a segment o fa circle and, subsequent to mold discharge, is carried by a guide track in the shape of a circle segment with provision being made for optimum cooling of the metal strip during passage therethrough by water spray impingement, with a maximal area of the guide track and strip passing therethrough being exposed to unimpeded spray cool treatment, and with minimal strip guide structures cooperating with the guide for maximum open area exposure of the cast billet for cooling.

3 Claims, 5 Drawing Figures PAIENIEuJuL24|9n 3.747. 667

sum 1 or 2 n J INVENTOR MQX/M ATTORNEY GUY F. CARLE 848 M BACKGROUND OF THE INVENTION Methods and apparatus for the continuous casting of metal strip have heretofore been devised, such as shown, for example, in US. Pat. No. 2,947,075, cated Aug. 2, 1960, entitled: METHOD FOR THE CONTIN- UOUS CASTING OF METAL STRIP, AND STRIP CASTING PLANT FOR CARRYING OUT THE METHOD. This curved, water cooled, six strand billet casting machine was found to have certain drawbacks or malfunctions in operation, and difficulties arose in producing billets therewith.

A major difficulty in prior known typesof apparatus has been occasional breakouts while the cast billet passes through the curved section. It was found that the center of the casting was still in a'molten condition when it cracked because the casting area was not exposed enough to solidify it when spray cooling, primarily because of underexposure of the cast area due to the construction of the apparatus. The molten metal, when breakouts occured, flowed throughout the structure, thereby making it inoperable and requiring a substantial amount of time to replace a damaged curved trough.

The present invention is directed to an improvement of the apparatus and method which eliminates these drawbacks or malfunctioning.

, BRIEF DESCRIPTION OF THE INVENTION The present invention, accordingly, is directed to improvements in method and apparatus for the continuous casting of metal strip or billets utilizing a curved guide track, and wherein guide structure associated with the track or chute is minimal, with a resultthat the billet casting has a much greater exposed area to the water spray for cooling, which accomplishes a faster cooling prior to'enteringwithdrawing pinch rolls.

According to the invention, it is notnecessary to remove structure from the foundation when trouble is encountered. By usinga cutting torch, the rejected material can be removed from the structure, and the chute is comprised of a plurality of sections which are interchangeable, one with another, for easy rapid replacement in case of breakage or wearing.

The sections are formed from a low-alloyed cast iron which prevents a steel billetcasting from gallingor scarring due to its lubricating qualities.

In essence, the invention teaches a lowalloy cast iron slide'located below a mold, having a small indentation cast on the bottom of the structure similar to the shape or size of materialemanatingfrom the mold. The billet slides freely without numerous guide supportson top and both sides, with substantially total exposure of the billet to a coolingmedium to actually solidify the material before shearing and eliminates breakout while traveling which, otherwise, causes a delay in production. Defective material is easily removed when necessary and repair requires a minimum of down time.

LII

Other and further objects and advantages of the invention will be more readily apparent from the following detailed description of an embodiment thereof when taken together with the accompanying drawings in which: i i

FIG. lis a schematic side view of the continuous casting apparatus of the invention;

2 FIG. 2 is a sectional view taken on line 22 of FIG.

FIG. 3 is an end elevational view, schematically shown taken generally on line 33 of FIG. 1;

FIG. 4 is a side elevational view of a guide roller and mounting structure; and

FIG. 5 is an end elevational view taken at right angles to FIG.4.

Referring in more detail to the drawings, the'apparatus includes a hopper 10 for molten metal adapted to be fed from a traveling crane, not shown. The metal flows from hopper 10 into a mold 12 having a casting chamber of slightly curvilinear configuration as shown in FIG. 1. The mold 12 is surrounded by a cooling jacket 14, which also surrounds casting chamber 16. Metal in the form of a strip as passed through casting chamber 16 then enters curved guide track 18 for subsequent solidification and hardening. This structure is mounted on housing frame 20 and, as shown, a cooling water inlet 22 and outlet 24 are provided to cooling jacket 14. v

The cast strip 30 after passing through the guide track 18 is acted on by first and second pairs 26 and 28 of driven takeoff rollers. Subsequently a plurality of direction rollers 32 convert the strip from a curvilinear configuration to a straight strip and it then passes to a withdrawal section, generally indicated 34, including a frame 36 mounting support rollers 38.

The curved track 18 consists of a plurality of interconnected sections 40. These sections are appropriately mounted and interconnected as generally indicated at 42 and can be replaced 'by one another. The present invention differentiates from the prior known structure inthat the curved trough or chute 18 uses a minimum number of guide rollers and the present structure does not have an enclosed'top or side guides. There are two guide roller assemblies 43 and44 operatively associated with guide chute 18, one assembly being at the top where the billet casting enters and one at the bottom. This compares with approximately 32 rollers in the previous known design. The open area of the roller assembly is indicated at 44 within frame 46 supporting the unit. Water spray piping 48 is provided on four sides as indicated in FIG.2 and the open billet casting area is exposed to the water spray which permits a greater degree of coolingprior to entering the pinch or takeoff rolls.

In the event of casing difficulties or'the like rejected material is readily removed by a cutting torch and each section is interchangeable with the others in caseof breakage or wearing. The guideroller structure is shown in greater detail in FIGS. 3-5 wherein the unit 44 includes frame 49 appropriately mounted on support frames 50 mounted on pins 52 forreplacement or the like. The roller 54 is mounted on shaft 56 supported by frame 49 as shown for coaction with the cast strip 30. The four sections constituting the guide chute or trough are constructed from a cast low alloy iron having a small indentation 58 cast on the bottom of the structure similar to the shape or size of the material emanating from the mold. The iron prevents the steel bil-= let casting from galling or scariing due to its lubricating or size of the material emanating from the mold which permits free sliding of the cast strip without guide supports on top and both sides. The structure provides substantially total exposure to a cooling medium to actually solidify the material before shearing and prevents breakout while traveling through the chute or guide which otherwise causes a delay in production and facilitates ease of removing defective material when necessary with substantially less down time.

Manifestly, minor changes in details of construction can be effected without departing from the spirit and scope of the invention asdefined in and limited solely by the appended claims.

I claim:

1'. Apparatus for the continuous casting of metal strips comprising:

A. a molten metal hopper;

B. a liquid cooled mold below said hopper having a slightly curvilinear strip casting chamber therein;

C. a downwardly extending elongated curvilinear open tovtop guide chute below said casting chamher for receiving a metal strip as cast in said casting chamber and supporting said strip through a cooling and solidifying zone with the top and upper side portions thereof exposed;

D. said guide chute comprising a plurality of interconnected and interchangeable sections to facilitate replacement in case of breakage or wearing;

B. said guide chute and said assemblies supporting and guiding said strip-with the exterior surfaces thereof substantially exposed for application of cooling liquid spray;

F. substantially open structure guide roller assemblies positioned solely proximate the entry and discharge ends respectively of said chute with strip support therebetween-being solely and uninterruptedly by said guide chute;

G. said guide roller assemblies including:

i. a strip bottom engaging and supporting slide; and ii. a strip top engaging roller;

H. said chute sections being constructed of cast low alloy iron having a small indentation cast into the bottom thereof similar in shape and size to the bottom portion of a cast strip and engageable with the bottom corners only thereof, the iron preventing galling or scarfing of the cast strip due to lubricating properties, and the so cast iron forming a slide supporting the bottom corners of and permitting free sliding of the cast strip without guide supports or contact areas on top and both sides, and substantially openly exposing bottom, side and top surfaces of the cast strip for application thereto of the liquid spray; I

cooling liquid spray means associated with said assemblies operable for substantially completely enveloping the exterior surfaces of the cast strip with cooling liquid. 7 v 2. Apparatus as claimed in claim 1, said guide roller assemblies including an open support frame member,

a frame mounted in said support member, and a strip guide roller mounted on said frame in coacting position with said slide and engageable with the top surface of a cast strip in said slide.

3. Apparatus as claimed in claim 2, including cooling liquid spray piping operatively positioned on sides of said support frame adapted for the substantial complete enveloping of the cast strip with cooling liquid. 

1. Apparatus for the continuous casting of metal strips comprising: A. a molten metal hopper; B. a liquid cooled mold below said hopper having a slightly curvilinear strip casting chamber therein; C. a downwardly extending elongated curvilinear open to top guide chute below said casting chamber for receiving a metal strip as cast in said casting chamber and supporting said strip through a cooling and solidifying zone with the top and upper side portions thereof exposed; D. said guide chute comprising a plurality of interconnected and interchangeable sections to facilitate replacement in case of breakage or wearing; E. said guide chute and said assemblies supporting and guiding said strip with the exterior surfaces thereof substantially exposed for application of cooling liquid spray; F. substantially open structure guide roller assemblies positioned solely proximate the entry and discharge ends respectively of said chute with strip support therebetween being solely and uninterruptedly by said guide chute; G. said guide roller assemblies including: i. a strip bottom engaging and supporting slide; and ii. a strip top engaging roller; H. said chute sections being constructed of cast low alloy iron having a small indentation cast into the bottom thereof similar in shape and size to the bottom portion of a cast strip and engageable with the bottom corners only thereof, the iron preventing galling or scarfing of the cast strip due to lubricating properties, and the so cast iron forming a slide supporting the bottom corners of and permitting free sliding of the cast strip without guide supports or contact areas on top and both sides, and substantially openly exposing bottom, side and top surfaces of the cast strip for application thereto of the liquid spray; I. cooling liquid spray means associated with said assemblies operable for substantially completely enveloping the exterior surfaces of the cast strip with cooling liquid.
 2. Apparatus as claimed in claim 1, said guide roller assemblies including an open support frame member, a frame mounted in said support member, and a strip guide roller mounted on said frame in coacting position with said slide and engageable with the top surface of a cast strip in said slide.
 3. Apparatus as claimed in claim 2, including cooling liquid spray piping operatively positioned on sides of said support frame adapted for the substantial complete enveloping of the cast strip with cooling liquid. 